MALDI-MS has been shown to be an effective analytical method for various complex carbohydrates, including oligosaccharides derived from glycoproteins. The introduction of post-source decay (PSD) analysis has demonstrated that sequence information can also be obtained from these molecules. However, because only sodium-cationized molecules are typically produced, the fragmentation patterns observed are often very complex. Reducing and non-reducing terminal fragments, cross-ring fragments and internal fragments are all produced, complicating sequence determinations. We have developed several new glycosylamine derivatives of the reducing terminus that simplify the fragmentation pattern of oligosaccharides in PSD analysis. One of these, the glycosylamine product derived from 3-aminoquinoline is particulaly promising because it produces primarily protonated molecules. PSD of the [M+H]+ ion yields a spectrum dominated by Y ions, allowing the sequence to be readily determined. An added advantage is that reaction cleanup is not necessary and excess reagent can be used as a MALDI matrix.